Even in this remarkable year of uprisings and unpredictable events, it was an inspirational moment that revealed the pace of change sweeping Africa. The veteran leader of a country whose party had become entrenched in office and been plagued by corruption allegations handed over the presidency after losing an election.

In a continent where all too often presidents cling on to power by any means necessary, Zambia's Rupiah Banda conceded defeat on Friday with astonishing grace and dignity. "My generation, the generation of the independence struggle, must now give way to new ideas – ideas for the 21st century," he said, with tears in his eyes.

His generous message of reconciliation and unity was greeted with relief in a former British colony that has been relatively stable since gaining independence, especially given flickers of violence sparked by slow counting of votes. After half a century in the public eye, the 74-year-old said he would go home to play with his children.

Banda deserves to be called one of Africa's big men. His fine words offer the sharpest possible reproach to the generation that has dominated the political landscape of Africa with often such dreadful consequences.

The reluctance of these old men to leave office has scarred the continent, especially given their propensity to pillage their nations, eliminate rivals and clamp down on free expression. It is not just the obvious tyrants such as Robert Mugabe, 87 years old and still ruining Zimbabwe, and Teodoro Obiang, whose repressive kleptocracy in Equatorial Guinea is now the longest-standing government in Africa.

In supposed democracies such as Senegal and Cameroon, elderly men long past retirement age are gearing up for elections at which they intend to retain their grip on power. As Uganda's veteran leader Yoweri Museveni once said, many of Africa's problems are caused by leaders who overstay their welcome – although that was before he stole another election earlier this year, extending his 25-year rule and provoking unrest.

Slowly but surely, however, things are changing – as shown by Zambia. Michael Sata, the silver-tongued victor who once worked for British Rail, may himself be from the liberation generation but he harnessed the frustrations of the young. He presented himself as a champion of the poor and vowed to tackle both unemployment and undue Chinese influence. The challenge now is whether the charismatic "King Cobra" can deliver on his promises.

Africa is an amazingly young continent, with nearly two-thirds of the population under 24. The young people of sub-Saharan Africa, connected by their mobile phones, are just as fed up with corruption and indignity as the youths who sparked the Arab Spring.

Given the demographics, the desire for change is irresistible. Democracy is spreading across the entire continent, bringing peace and increased prosperity in its wake. It has been given a huge boost this weekend by an old man in Zambia throwing down a challenge to the generation that freed their nations from their colonial rulers.

The refusal of another president to give up power in the Ivory Coast provoked a civil war and huge media coverage. The actions of Mr Banda attracted minimal discussion. In the long run, however, they show the real face of a changing continent.

• This article was amended on 27 September 2011. The standfirst, "Zambia's long-standing president stands down after losing an election… a sign that the continent's fortunes might be changing for the better", was amended to read "Zambia's president stands down after losing an election… a sign that the continent's fortunes might be changing for the better"